Management of potato bacterial wilt using plant extracts, essential oils, antagonistic bacteria and resistance chemical inducers [electronic resource].

Includes references.

Twenty isolates of Ralstonia solanacearum were isolated from naturally infected potato plants, collected from different localities of Assiut and Sohag Governorates. The isolate M4 exhibited the highest wilt severity by M6, M12, A16 and E17 isolates. The effectiveness of plant extracts, essential oils, antagonistic bacteria and resistance chemical inducers in controlling the bacterial wilt disease on potato cv. Diamont under greenhouse and field conditions was evaluated. Among all tested materials, only plant extracts of Hibsicus sabdariffa. Eucalyptus globulus and Punica granatum found to be able to inhibit the growth of bacterial pathogen in vitro. In greenhouse experiment, all tested treatments significantly reduced disease severity. Soil drench applications with 50 ml plant extracts/pot of Eucalyptus globulus, Hibiscus sabdariffa and Punica granatum and thyme oil, reduced profoundly disease severity by 94.17, 89.05, 78.99 and 84.83%, respectively. Application of clove oil, plant extract of Datura metel and Pseudomonas fluorescens caused intermediate disease severity. Population of R. solanacearum was lowest in stems of potato plants treated with plant extracts and thyme oil than in inoculated control; however, other tested treatments caused slight effect. Under field conditions application of plant extracts. Salicylic acid and Pseudomonas aeruginosa caused highest reduction in severity of bacterial wilt, marked increase of fresh and dry weight of potato plants and tubers yield. However, application of bacterial suspension of Pesudomonas flurescens, acibenzolar-S-methyl and clove oil showed slight reduction in disease severity and moderate increase in both tuber yield and fresh and dry weights of plants.

Summary in Arabic.

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